Labelling machines are used in the beverage processing industry in order to apply continuously labels to consistently fed articles or containers with high performance. Thereby, the containers may be cans, glass bottles, plastic bottles or the like. In addition to self-adhesive labels, also labels are known onto which initially glue is applied in order to subsequently apply the labels provided with glue onto the containers. Appropriate glue, for example, is applied onto the rear sides of the labels via a gluing device by means of a glue roller. This may occur directly by applying the glue by means of the glue roller to the labels passing by means of a vacuum cylinder. However, it may also occur indirectly by initially transferring the glue by means of a glue roller to the curved adhesive surface by extraction elements which are moved past the glue roller in an oscillating or rotating manner, so-called pallets which for their part remove separately the labels from a label stack, whereby during removing, the labels are provided on the rear side with the glue that beforehand has been transferred. The now glued labels are subsequently transferred to a rotating gripper cylinder or the like, from where they are transmitted to the containers.
In both cases, the required glue initially has to be transferred by a storage container for glue to the glue roller. For this, the glue is usually pumped from the storage container to a glue application unit by means of a pump and is applied thereto over the entire axial extent of the glue roller. Document DE 3022040 A1, for example, describes a glue roller to which a glue application element and an adjustable glue scraper are assigned. Thereby, the glue drained from the storage container by means of the glue scraper is transferred to the glue roller. Regularly, the glue scraper is configured pivotedly mounted and abuts tangentially the glue roller in axial direction of the glue roller. The positioning of the glue scraper at the glue roller, thereby, is of great importance for an optimal labelling result. During applying the glue on the glue roller, a so-called glue string is formed extending over the entire height of the glue roller.